A hundred years ago a dozen popular magazines with names like McClure’s, Hampton’s and Collier’s made their livings exposing the dirt collecting under the plush carpet of American capitalism.

These “muckraking” magazines, as President Teddy Roosevelt dubbed them, hammered away passionately at real and imagined ills of American society, largely from a socialist-progressive point of view that today appeals mostly to followers of Ralph Nader.

Writers like Ida Tarbell, Lincoln Steffans and Will Irwin became national heroes, cranking out subjective attacks on everything from corrupt big-city governments to food adulteration and the predatory practices of John D. Rockefeller and his fellow robber barons.

Old-fashioned muckraking hardly exists today in the mass media, which, considering the media’s left-liberal tilt, is probably a good thing. About the only place you can consistently find it is in Mother Jones, the left-wing magazine that, though its pro-union, anti-capitalistic politics are annoying, deservedly won a National Magazine award for general excellence earlier this year.

Mother Jones’ cover for July/August, a hard-hitting report on the dangers of working in America’s slaughterhouses by Eric Schlosser, is a perfect example of modern muckraking.

Schlosser is the author of “Fast Food Nation,” the best-selling expose of the junk-food industry which, if read by enough people, may send McDonald’s stock into a permanent tailspin and turn half the country’s cheeseburger addicts into vegans.

In the course of visiting meatpacking plants while researching “Fast Food Nation,” Schlosser discovered for himself why the meatpacking industry has become the most dangerous occupation in America.

According to government statistics quoted by Schlosser, more than a quarter of the industry’s 150,000 low-paid workers were hurt or became sick on the job in 1999 – many of them seriously.

Until the 1960s, Schlosser says, the meat industry was decentralized and, despite its inherently horrible working conditions, it had a reasonably well-paid, highly skilled union workforce.

Now, he says in a solidly reported piece of advocacy journalism that focuses on several workers who’ve lost various parts of their bodies to meat-chewing machinery, four powerful corporations control 85 percent of the market.

Schlosser explains how these politically connected companies now use assembly line methods, hire mostly unskilled non-union immigrants and work them too hard and fast in dangerous conditions.

Then, when they inevitably get hurt, the companies put them back to work too soon, lay them off, or try to cheat them out of their health and medical benefits at every opportunity.

Society also pays a high cost, Schlosser says. “Each new year throws more injured workers on the dole, forcing taxpayers to subsidize the meatpacking industry’s poor safety record. No government statistics can measure the true amount of pain and suffering in the meatpacking communities today.”

The processing of animal flesh for America’s meat-eating culture is not pretty, but it’s not as stomach-turningly gross as it was when Upton Sinclair wrote “The Jungle.”

And though the meatpacking industry no doubt would like additional space in Mother Jones to tell more of its side of things, Schlosser’s exercise in old-fashioned muckraking makes a strong case that workers – unionized or not – are getting the butt-end of the roast.